/*
 * Copyright (c) 2005, 2006, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 */
package javax.swing.plaf.nimbus;

import sun.awt.AppContext;

import java.awt.image.BufferedImage;
import java.lang.ref.SoftReference;

/**
 * Effect
 *
 * @author Created by Jasper Potts (Jun 18, 2007)
 */
abstract class Effect {

  enum EffectType {
    UNDER, BLENDED, OVER
  }

  // =================================================================================================================
  // Abstract Methods

  /**
   * Get the type of this effect, one of UNDER,BLENDED,OVER. UNDER means the result of apply effect
   * should be painted under the src image. BLENDED means the result of apply sffect contains a
   * modified src image so just it should be painted. OVER means the result of apply effect should
   * be painted over the src image.
   *
   * @return The effect type
   */
  abstract EffectType getEffectType();

  /**
   * Get the opacity to use to paint the result effected image if the EffectType is UNDER or OVER.
   *
   * @return The opactity for the effect, 0.0f -> 1.0f
   */
  abstract float getOpacity();

  /**
   * Apply the effect to the src image generating the result . The result image may or may not
   * contain the source image depending on what the effect type is.
   *
   * @param src The source image for applying the effect to
   * @param dst The dstination image to paint effect result into. If this is null then a new image
   * will be created
   * @param w The width of the src image to apply effect to, this allow the src and dst buffers to
   * be bigger than the area the need effect applied to it
   * @param h The height of the src image to apply effect to, this allow the src and dst buffers to
   * be bigger than the area the need effect applied to it
   * @return The result of appl
   */
  abstract BufferedImage applyEffect(BufferedImage src, BufferedImage dst, int w, int h);

  // =================================================================================================================
  // Static data cache

  protected static ArrayCache getArrayCache() {
    ArrayCache cache = (ArrayCache) AppContext.getAppContext().get(ArrayCache.class);
    if (cache == null) {
      cache = new ArrayCache();
      AppContext.getAppContext().put(ArrayCache.class, cache);
    }
    return cache;
  }

  protected static class ArrayCache {

    private SoftReference<int[]> tmpIntArray = null;
    private SoftReference<byte[]> tmpByteArray1 = null;
    private SoftReference<byte[]> tmpByteArray2 = null;
    private SoftReference<byte[]> tmpByteArray3 = null;

    protected int[] getTmpIntArray(int size) {
      int[] tmp;
      if (tmpIntArray == null || (tmp = tmpIntArray.get()) == null || tmp.length < size) {
        // create new array
        tmp = new int[size];
        tmpIntArray = new SoftReference<int[]>(tmp);
      }
      return tmp;
    }

    protected byte[] getTmpByteArray1(int size) {
      byte[] tmp;
      if (tmpByteArray1 == null || (tmp = tmpByteArray1.get()) == null || tmp.length < size) {
        // create new array
        tmp = new byte[size];
        tmpByteArray1 = new SoftReference<byte[]>(tmp);
      }
      return tmp;
    }

    protected byte[] getTmpByteArray2(int size) {
      byte[] tmp;
      if (tmpByteArray2 == null || (tmp = tmpByteArray2.get()) == null || tmp.length < size) {
        // create new array
        tmp = new byte[size];
        tmpByteArray2 = new SoftReference<byte[]>(tmp);
      }
      return tmp;
    }

    protected byte[] getTmpByteArray3(int size) {
      byte[] tmp;
      if (tmpByteArray3 == null || (tmp = tmpByteArray3.get()) == null || tmp.length < size) {
        // create new array
        tmp = new byte[size];
        tmpByteArray3 = new SoftReference<byte[]>(tmp);
      }
      return tmp;
    }
  }
}
